A wireless interactive video system disclosed in U.S. Pat. No. 4,591,906, May 27, 1986, Fernando Morales-Garza, et al. provides for real time interactive digital communication from a large audience of subscribers in urban areas in the vicinity of a central television transmitting station.
The Federal Communications Commission (FCC) has now established in the U.S.A. communication standards for such interactive video data service allocating wireless transmissions in the 218-219 MHz band for FCC licensing for public use in assigned local base station areas authorizing low power subscriber interaction units of maximum effective radiated power under twenty watts.
There has been no known interactive video data service system available heretofore that has the capability of servicing an assigned base station area with subscriber units transmitting in a milliwatt power range. With such an improved system, battery powered, portable subscriber units, suitable for such functions as meter reading, would become feasible with low battery drain, permitting interactive digital communication in local areas or nationwide.
Wireless interactive video data service is provided without telephone lines or cable systems over a nationwide network of base stations in the manner disclosed in U.S. Pat. No. 5,101,267, Mar. 31, 1992, Fernando Morales, by way of satellite transmissions between local area base stations and a data center.
This nationwide communication capability permits live video programs viewed nationwide, such as world series baseball games, to become interactive for individual subscriber participation. Thus, mass communications over a substantially real time communication system with such large urban area audience participation that would jam any existing public telephone switching network capability are made feasible.
Each local base station in such a nationwide communication system must be capable of interacting within designated license restrictions in the presence of peak local audience participation without significant switching delays to establish substantially real time interactive two-way connections over a network processing an audience of very large numbers of participants wishing to communicate substantially simultaneously.
Prior art two-way radio transmission network technology, as represented for example by portable telephone communication systems, is generally incompatible with efficient substantially real time communication in the presence of heavy subscriber activity. This occurs because in telephone systems switching and connection operations must be made compatible with switching instructions from subscriber instruments with coded audio tones at audio frequencies accompanying analog audio messages. Thus with long numeric identification numbers for nationwide long distance connections, typically of ten decimal digits, which must be manually entered while busying lines to complete point-to-point connections as a part of the interconnecting signal data, switching circuits are engaged for very long periods of time inconsistent with substantially real time connections or heavy traffic conditions. Accordingly busy signals are encountered often to restrict the size of a participating audience for immediate connection and the follow-up contention for a line requiring re-dialing is frustrating to the potential using audience. Thus, interactive response that requires telephone exchange communications tends to be delayed and discouraging to participants, and introduces the critical problem of identifying and communicating interactively between subscribers in real time without jammed exchanges and the frustration of encountering busy signals and starting over with a new attempt to communicate.
Similarly, even with the restricted amount of digital data that might be transferred in digital paging system messages, where typically some messages only indicate a short fixed length message such as a calling telephone number, there is little possibility of approaching real time communications in the presence of heavy traffic because of the complexities of the necessary telephone switching networks employed for conveying messages.
In order to process digital information accurately, efficiently and privately it is necessary to precisely time and organize the digital data and accompanying commands. For real time two-way digital communications with large audiences wanting prompt access to the message conveyance system or network, synchronous signal timing becomes critical and absolutely necessary for real time interactive communication. In general audio telephone communications are of an analog nature not critical to timing and are conveyed asynchronously. Thus, prior telephone art signal communication systems are unsuited for adoption in interactive video data systems that convey private point to point digital messages on a real time basis for large audiences.
Typical patents relating to nationwide communications employing such prior art telephone switching techniques are now briefly referenced as representative of the present state of the art utilizing analog (voice) telephone communication networks and cellular technology to accommodate low-cost mobile battery-operated subscriber units operable within local cellular subdivisions.
In the telephone arts: Freeburg, U.S. Pat. No. 4,481,670, Nov. 6, 1984 and U.S. Pat. No. 4,525,861, Jun. 25, 1985 and 4,550,443, Oct. 29, 1985 provide for handing off best signals from portable radio sets in two-way audio analog communications between overlapping zones served by different fixed location cellular transceivers, which in some cases use different frequency bands for isolating adjacent zones.
In the paging arts, modems are used for connection with a telephone system for communication and switching over a national network as typically set forth in Andros, et al. patents U.S. Pat. No. 4,870,410, Sep. 26, 1989 and U.S. Pat. No. 4,875,039, Oct. 17, 1989, and therefore are subject to the same switching system bottlenecks previously described even when short digital only communication is desired.
It is accordingly an objective of this invention to improve the state of the art by effectively using licensed interactive communication channels to provide substantially real time, synchronously timed digital communications of variable length between geographically separated base station subscribers of an interactive video data service system. Capacity for heavy audience participation without substantial delays during peak loading conditions is essential in a manner compatible with the FCC licensing conditions for interactive video data service.
It is a further objective of this invention to introduce into interactive video data service a system providing effective two-way interactive communications with simplified low-cost subscriber units transmitting in milliwatt peak power ranges under parameters compatible with FCC licensing restrictions.
Another object of the invention is to introduce portable digital communication subscriber units into an interactive video data service system adapted for local and national communications.
Other objects, features and advantages of the invention will be found throughout the following description, the drawings and the claims.